The invention relates to a method of winding a web in a machine for processing printing materials and, more particularly, includes controlling the winding of the web into a roll as a function of the diameter of the roll being formed by the web, as the diameter changes during the winding, and a winding device for machines for processing printing materials, including equipment for winding a web up into a roll, and a first feeler for monitoring the diameter of the web, as the diameter changes during the winding of the web into the roll.
In order to clean rollers or cylinders in printing machines, washing devices are provided which are constructed as slide-in or insert elements having cleaning cloths which are unwindable from supply rolls.
Such a washing device is described in the published German Patent Document DE 39 09 119 A1. When it is being inserted or slid into the printing machine, it is automatically couplable mechanically to a roll checking device affixed to the machine.
Strictly speaking, although a proximity switch of the roll checking device is arranged so as to be affixed to the machine, a sensing plate thereof resting on the roll of cloth is not. The only sensing plate of the roll checking device is arranged on the slide-in or insert element.
The washing device described in the aforementioned published German patent document, however, is practically not usable as a reserve washing device for optional or selective insertion into different printing machines. If the washing device, after being removed from a printing unit and after the dirty cleaning cloth thereof has been replaced by a fresh cleaning cloth, were to be inserted into a different printing unit, complicated adjustments would be required each time.
The published German Patent Document DE 29 507 134 U1 makes reference to this inadequacy. A device described therein for washing cylinders or rollers should certainly be exchangeable desirably between the individual printing units, but nevertheless, the device is not easy to handle and is susceptible to failure. The entire cloth checking mechanism and a sensing tongue belonging to the latter are mounted on a side part removable from the printing machine and are not affixed to the machine. The sensing tongue is a hindrance when the cleaning cloth is being replaced outside the printing machine and can, as a result of careless handling, be damaged, which makes precise checking of the roll impossible.
In the published German Patent Document DE 42 33 953 A1, a washing device for a printing-machine cylinder is described, which has a washing bar, and a cleaning cloth-end indicator fixed in position on the printing-machine frame and serving for generating a machine shut-off signal that is produced shortly before the end of a cleaning cloth and is generated even when the washing bar with the cleaning cloth is not in a washing position. This published German patent document does not describe specifically what type of indicator is being referenced.
In addition, the published German Patent Document DE 195 43 518 A1 describes a device for washing cylinder jacket surfaces wherein, in the operating position thereof, a supply of cloth on a supply roll is monitored by sensors which are brought into a functional position when inserted. This published document does not contain any specific statements relating to the mounting of the sensors.
It is accordingly an object of the invention to provide a method for winding up a web into a roll in a machine for processing printing materials, wherein a critical diameter of the roll is precisely determined, and to provide a device for performing the method, which has a feeler or sensor that is reliably protected against damage.
With the foregoing and other objects in view, there is therefore provided, in accordance with one aspect of the invention, a method of winding a web band in a machine for processing printing materials, including controlling the winding as a function of a diameter of a roll formed by the web band, as the diameter changes during the winding, which comprises determining, by a first sensor fastened to a frame of the machine, the position of a peripheral surface of the roll relative to the frame of the machine, and determining, by a second sensor fastened to the frame of the machine, the position, relative to the frame of the machine, of either a center of the roll or of a peripheral surface of a spindle carrying the roll.
In accordance with another mode, the method, wherein the sensors are feelers, includes, by a first feeler resting on the roll formed by the web band, monitoring the diameter of the roll formed by the web band, as the diameter changes during the winding, and interrupting the winding when the roll has reached a critical diameter, and sensorally monitoring the mutually relative positions of the first feeler and of a second feeler.
In accordance with a further mode, the method includes sensorally monitoring mutually relative angular positions of the feelers.
In accordance with another aspect of the invention, there is provided a winding device for a machine for processing printing materials, comprising a web band windable into a roll, a first feeler for monitoring a diameter of a roll being wound as the diameter changes during the winding, the first feeler being mounted affixed to a frame of the machine.
In accordance with another feature of the invention, the winding device includes a second feeler assigned to the first feeler.
In accordance with a further feature of the invention, the second feeler is mounted affixed to the frame of the machine.
In accordance with an added feature of the invention, the winding device includes a sensor assigned to the feelers for monitoring the mutually relative positions thereof.
In accordance with an additional feature of the invention, the sensor is applied to one of the feelers.
In accordance with yet another feature of the invention, the winding device includes a protective covering of the machine coupled with the first feeler via a mechanism.
In accordance with yet a further feature of the invention, the web band is a cleaning cloth.
In accordance with an additional aspect of the invention, there is provided a machine for processing printing materials having at least one winding device with at least one of the foregoing features.
In accordance with a concomitant feature of the invention, the machine for processing printing materials is a printing press having at least one winding device with at least one of the foregoing features thereof.
The method according to the invention ensures the precise determination or registration of the critical diameter of the roll, so that the web band length is optimally utilized, and the end of the web is nevertheless detected and held fast reliably.
Both when the sensors are constructed as contacting feelers, as well as when the sensors are constructed as contact-free measuring sensors, for example, as ultrasonic or infrared sensors, these sensors can be connected to an. electronic computer for evaluating a differential measurement.
The second sensor transmits to the computer a first signal corresponding either to a distance of the center of the roll or to a distance of the peripheral surface of the roll, from the frame, and the first sensor transmits to the computer a signal corresponding to the distance of the peripheral surface of the roll from the frame.
From the two signals, the computer automatically calculates a differential signal which is proportional to the radius of the roll, which changes during the winding, and is therefore proportional to the length of the web band wound up on the roll.
This web-band length can be indicated to the operator via an indicating device connected to the computer, for the purpose of making-ready or preparing the replacement of the web band.
The computer is capable of stopping a drive effecting the rotation of the roll, so that the winding operation is interrupted when the differential signal has fallen below a specific value.
In a preferred mode of the method according to the invention, the sensors which are used are feelers contacting the measurement locations.
The method can be implemented effectively with the winding device according to the invention. The beneficial factor in the winding device is that the web band thereof and an unwinding- spindle, spool or roller from which the web band is unwound, can be removed without removing the first feeler from the printing-material processing machine. During the replacement of the web band, the first feeler can remain in the processing machine, where it is protected against damage and is not a hindrance during the replacement of the web band.
In an embodiment of the winding device according to the invention, which is advantageous with regard to the use of the winding device as a reserve device provided for use in various machines which process printing materials or in various components of a machine that processes printing materials, the first feeler has a second feeler assigned thereto.
In addition, this embodiment is advantageous with regard to implementing the method according to the invention.
The winding device having a second feeler in addition to the first feeler is preferably constructed in a manner corresponding to that of the winding device having only the one feeler which is mounted in a fixed location on a frame of the machine, and can also be a winding device constructed differently therefrom. The presence of two feelers also results in advantages with regard to the precise presetting of the first feeler by the second feeler without requiring adjusting work to be performed manually and without excessive time-consumption, even in the case of winding devices having a first feeler that is not mounted in a fixed position on the frame of the machine.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as a winding method and device for machines for process printing materials, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.